Error Prevention for Important Transactions: The Decisions That Matter
Safeguards on forms that create legal commitments, move money, change stored data or submit test answers, so mistakes can be caught before they count.
Marcus Adeyemi
What is at stake
An error in a payment or legal submission can be costly and hard to reverse, and WCAG requires review, confirmation or reversal for these at level AA.
The playbook
- Add a review step before payments and agreements
- Let users edit details from the review page
- Offer cancellation or undo windows where possible
- Confirm deletions of stored data
- Validate inputs before the final step
Where it goes wrong
Avoid:
- One-click submission of legal agreements
- Irreversible deletions with no confirmation
- Review pages that cannot be edited
- Hiding cancellation options
The numbers behind it
| Measure | Figure |
|---|---|
| WCAG 3.3.4 Error Prevention (Legal, Financial, Data), AA | submissions are reversible, checked for errors, or reviewed and confirmed |
| Covered situations | legal commitments, financial transactions, changes to stored data and test responses |
| Common technique | a review page before final submission |
| WCAG 3.3.6, AAA | extends the same protection to all submissions |
Getting outside help
When to hand it over: Bring in help when designing checkout, banking, insurance or government forms.
Where this comes from
- W3C Web Accessibility Initiative — Understanding SC 3.3.4 Error Prevention (Legal, Financial, Data)
- GOV.UK Design System — Check answers pattern
The figures and practices above come from the sources listed.
Working on something like this?
We take on Performance & Accessibility work for teams who want it done once, properly. Tell us what you are building and we will tell you honestly whether we are the right studio for it. Start a project.
Where to go next
Spotted something wrong? Report an error on this page. We correct on the page and say what changed.
